Field of the Disclosure
The embodiments herein relate to an organic light emitting device, and more particularly, to an organic light emitting device with a touch sensor.
Discussion of the Related Art
Among various flat display devices, a liquid crystal display (LCD) device has been widely used up to now. However, the LCD device inevitably requires a backlight unit, and also shows limitation in brightness and contrast ratio. In contrast to the LCD device, an organic light emitting device can emit light in itself, that is, the organic light emitting device needs no additional backlight unit, and obtains relatively better brightness and contrast ratio. Thus, there is an increasing interest for the organic light emitting device.
The organic light emitting device may include a cathode for injecting an electron, an anode for injecting a hole, and a light emitting layer provided between the cathode and the anode. In this case, the electron generated in the cathode and the hole generated in the anode are injected into the inside of the light emitting layer, and the injected electron and hole combine to generate an exciton. When the generated exciton falls from an excited state to a ground state, a light emitting state occurs, whereby an image is displayed on the organic light emitting device.
Generally, the organic light emitting device uses an input means such as mouse or key board. However, when the organic light emitting device is applied to products such as navigation, mobile phone or PDA, a touch sensor is widely used, which allows a user to input information by directly touching a screen with a finger, a pen or the like.
Hereinafter, a related art organic light emitting device with a touch sensor will be described with reference to the accompanying drawings.
FIG. 1 is a cross sectional view illustrating a related art organic light emitting device.
As shown in FIG. 1, the related art organic light emitting device may include a lower substrate 10, a component layer 20, a barrier layer 30, a polarizing film 40, a touch sensor 50, an upper substrate 60, and an adhesive layer 70.
The lower substrate 10 is generally formed of glass. However, in order to realize a flexible organic light emitting device, which is capable of being bent or curved, the lower substrate 10 may be formed of transparent plastic material.
The component layer 20 is formed on the lower substrate 10, wherein the component layer 20 corresponds to a layer for performing a main function of the organic light emitting device for displaying an image. The component layer 20 may include a thin film transistor and an emitting component.
The barrier layer 30 is formed on the component layer 20, wherein the barrier layer 30 prevents external water or moisture from being permeated into the component layer 20.
The polarizing film 40 is formed on the barrier layer 30, wherein the polarizing film 40 prevents a reflection of external light. That is, when the external light is incident on the upper substrate 60, and is then provided to the inside of the organic light emitting device, the light may be reflected on a plurality of electrodes or lines formed inside the component layer 20, which might cause a viewer's inconvenience for watching a displayed image. According as the polarizing film 40 is applied to the organic light emitting device, it is possible to prevent the reflection of external light. The polarizing film 40 performing this function may be generally formed of a circular polarizing plate.
The touch sensor 50 is formed on the polarizing film 40. The touch sensor 50 may include a first touch sensor 50a for sensing a touch position in the X-axis direction, and a second touch sensor 50b for sensing a touch position in the Y-axis direction. Each of the first touch sensor 50a and the second touch sensor 50b includes a touch electrode provided with a predetermined pattern on a base film.
The upper substrate 60, which is provided in the uppermost surface of the organic light emitting device, protects the organic light emitting device.
The adhesive layer 70 may include a first adhesive layer 70a, a second adhesive layer 70b, a third adhesive layer 70c, and a fourth adhesive layer 70d. First, the polarizing film 40 adheres to the barrier layer 30 by the use of first adhesive layer 70a, the first touch sensor 50a adheres to the polarizing film 40 by the use of second adhesive layer 70b, the second touch sensor 50b adheres to the first touch sensor 50a by the use of third adhesive layer 70c, and the upper substrate 60 adheres to the second touch sensor 50b by the use of fourth adhesive layer 70d. That is, since the polarizing film 40, the first touch sensor 50a, the second touch sensor 50b, and the upper substrate 60 are manufactured in a separate unit, it inevitably requires the adhering process for combining the above separately-manufactured components together by the use of additional adhesive.
However, the related art organic light emitting device has the following disadvantages.
As mentioned above, the related art organic light emitting device includes the plurality of separately-manufactured components, and thus it also needs the plurality of adhesive layers such as the first adhesive layer 70a, the second adhesive layer 70b, the third adhesive layer 70c, and the fourth adhesive layer 70d. 
According as the number of adhesive layers is increased, a thickness of the organic light emitting device is also increased so that it is difficult to realize the organic light emitting device with a thin profile. Due to the increased thickness of the organic light emitting device, a radius of curvature is increased in the organic light emitting device, whereby it is difficult to realize the flexible organic light emitting device which is capable of being bent or curved with easiness.